The 50% rule is like using the acid test ratio, or quick ratio, it's a good initial indication, but it does not replace crunching the numbers.When you get to more advanced investing strategies, you'll begin looking at:Tax benefits,Possible appreciation,Rent demands and repricing of rents,Change of use of the property,Financial leveraging benefits,Flip possibilities,and much more.Using the 50% rule alone would be like making a buy decision based on the earnings per share last quarter of Wal-Mart stock, IMO.

I know boric acid is one that can kill the roaches.Thank you kindly

Such a waste of time giving me acid stomach.

Marble is alkaline and reacts with acidic stuff (tomatoes, oranje juice, etc.) and is unsuitable for kitchens.

I guess a worse case is an acid wash.  

Okay met the bug guy today at my complex.He said the problem I have is German cockroaches.Stated tenants have to stay clean or bug problem won't go away and that all tenants have to be clean or bugs will spread to other units in the building.We are going to be doing inspections to the units once a month.If tenants are not keeping clean I will file for eviction on them immediately.Bug company wanted a crazy amount 500 month for 20 units in 5 buildings.What I ended up doing is one building at 100 a month.This building had tenants I just got out and the unit was really bad with roaches.Said one of the worst he has ever seen.The other 4 buildings have no current bug problems that I know of.I know I can buy Boric acid and the gels myself but if you would have seen this unit you would gladly pay the money.Bug guy said after a few months I could save by going quarterly and I can cancel anytime.I also didn't want the liability of putting down pest control substance in tenants apartments and wanted to leave that to the professionals.Any comments appreciated.

The low porosity granite is more durable against acids and stains.

The brick buildings definitely are appealing but keep in mind that brick is 100+ yrs old and takes a beating from the moisture off the lack and the acid rain.

If I can nail down the number for health care I'll begin my 1 year acid test this winter (live off the rental net rental income - banking the health care cost and my day job wages) to see how feasible  retiring from the day job would be.

Everything I've seen is that copper lasts longer than PEX except in very acidic water.